Abstract: An image of a document is divided into a plurality of areas, and a reliability is obtained for each area for a case where an image of the area is used in orientation detection. The reliability is obtained from characteristics of the shape of a histogram generated from image data of the area, as follows. The histogram is divided into a plurality of sections, and an MTF value is calculated for each section by dividing a difference of the max and min values of the section by the sum of the max and min values. A mean value of the MTF values calculated for all of the sections of the histogram is set as the reliability of the area. The orientation detection processing is performed on the area whose reliability is the highest, and an orientation result obtained through the orientation detection processing is judged as the orientation of the image of the document.

Abstract: An image input device identifies what part of the optical input system needs cleaning when there is dust or other foreign matter in the optical input system. This image input device has an image noise position detector for capturing image data from a scanner, and detecting the main scanning address of noise information corresponding to image noise present in the image data; a focus calculator for calculating focus information around the main scanning address detected by the image noise position detector; focus information storage for storing focus information for each subscanning line; and a foreign matter position determining circuit for determining the location of foreign matter on the scanner based on the focus information stored in the focus information storage.

Abstract: Image distortion is corrected in a color printer wherein print units for a plurality of colors are aligned to form a color image by superposing images formed by the print units. A quantity of image distortion is detected, and correction data of main scan address and subscan address are calculated and stored according to the detected image distortion for each main scan address. When input color image data are corrected, printing position is corrected in combination of address change with density interpolation. When the correction data exceeds the maximum correction range, the correction data are replaced by the maximum in the correction range to utilize the capability of the distortion correction of the printer. Further, in the image data correction, after the image data are converted to data having a smaller number of gradation levels, the data are delayed according to the serial arrangement of the print units. Then, the delayed data are converted again for printing.

Abstract: An image processing apparatus is provided with a binarization processing unit separately from a pseudo gradation processing unit that binarizes image data of a document image according to an error diffusion method. The binarization processing unit binarizes the image data of the document image using a threshold that is set higher than a threshold used by the pseudo gradation processing unit, with each threshold representing a different predetermined density level. Histograms showing the density distribution of the document image are generated from the image data binarized by the binarization processing unit. The orientation of the document image is recognized by the histograms.

Abstract: Image distortion is corrected in a color printer wherein print units for a plurality of colors are aligned to form a color image by superposing images formed by the print units. A quantity of image distortion is detected, and correction data of main scan address and subscan address are calculated and stored according to the detected image distortion for each main scan address. When input color image data are corrected, printing position is corrected in combination of address change with density interpolation. When the correction data exceeds the maximum correction range, the correction data are replaced by the maximum in the correction range to utilize the capability of the distortion correction of the printer. Further, in the image data correction, after the image data are converted to data having a smaller number of gradation levels, the data are delayed according to the serial arrangement of the print units. Then, the delayed data are converted again for printing.

Abstract: In an image processor, after the background of input image data is removed, the image data are divided into a plurality of areas, and the attribute of image is discriminated for each area. The image data after the background removal is compressed according to the result of attribute discrimination. The amount of the background removal can be controlled. Preferably, the amount of the background removal is controlled according to the discriminated attribute. Then, the background can be removed without artificial feeling in a reproduced image.

Abstract: In an image processor, multi-level image data are divided into blocks, and compressed in the unit of block. The compressed multi-level image data of a block are converted to compressed bi-level image data without expanding the multi-level image data. For example, the compressed multi-level image data on an image of uniform density are converted to compressed bi-level image data expressed with area gradation. In another image processor, the compressed multi-level image data of a block are converted to compressed multi-level image data, without expanding the multi-level image data. For example, the compressed multi-level image data on an image of bi-level image expressed with area gradation are converted to compressed multi-level image data of a half-tone image.

Abstract: In an image processor, after the background of input image data is removed, the image data are divided into a plurality of areas, and the attribute of image is discriminated for each area. The image data after the background removal is compressed according to the result of attribute discrimination. The amount of the background removal can be controlled. Preferably, the amount of the background removal is controlled according to the discriminated attribute. Then, the background can be removed without artificial feeling in a reproduced image.

Abstract: A printing system is provided in which a printer and a server are connected to a network. The server performs service to a terminal on behalf of the printer after the start of the printer activation and before the completion thereof, the service being such as instructing printing and receiving print data. The server, after receiving a completion notification of activation from the printer, instructs the terminal to suspend a print sequence, transfers, to the printer, the print data received on behalf of the printer, and instructs the terminal to cancel suspending the print sequence.

Abstract: In an image processing system in which a server, a plurality of image processing apparatuses that execute image quality stabilization processing, and a terminal apparatus are connected to each other via a network, the server calculates, with respect to each image processing apparatus, the time period elapsed since the image quality stabilization processing was last executed, and selects the apparatus having the shortest elapsed time period as the apparatus to execute a job requested by the terminal apparatus.

Abstract: In an image processing system in which a plurality of image processing apparatuses and a management apparatus are connected to each other via a network, the management apparatus forms the image processing apparatuses into one or more groups based on apparatus attribute information, acquires control variable value information from an image processing apparatus in a group, and sends the acquired information to the other image processing apparatuses in the group. The other image processing apparatuses receive the control variable value information sent from the management apparatus, and execute image processing based on the received information.

Abstract: A color image is formed by a color printer by superposing images of a plurality of colors formed by a plurality of print units. A discrimination signal which represent character edge is received besides image data. The print positions of the print units are corrected according to image distortion detected by a sensor, and the image data are corrected according to corrected print position data. Further, the discrimination signal of character edge is corrected according to the detected image distortion. A color image is formed based on the corrected image data and the discrimination signal of character edge.

Abstract: In an image processor, a decider decides based on image data of pixels included in a block whether the block has character attribute of non-character attribute, a first encoder encodes the image data with block truncation coding, and a second encoder encodes the image data which have been encoded by the first encoder. For a block of character attribute, the binarized data binarized by the binarizer are encoded by the first and second encoders. For a block of non-character attribute, the image data are encoded by the first and second encoders without binarization. In a different image processor, it is decide whether image data of pixels in an area consisting of a plurality of blocks are all character, all ground or mixture of character and ground. Then, an encoder encodes the image data in each block differently according to the decision.

Abstract: An image forming apparatus has an electrophotographic part for printing a monochromatic image and an ink jet part for printing a color image. A switch device selects to carry a sheet of paper which has been printed by the electrophotographic part directly to the external tray or to carry the sheet of paper through an intermediate tray to the ink jet part for printing a color image. Once the switch device selects to carry the sheet of paper to the ink jet part, the switch device is inhibited to discharge directly a sheet of paper on which an image is formed by the electrophotographic part. Thus, the order of the printed papers is kept the same as that of the original documents.

Abstract: An image processing apparatus has a data conversion unit which converts RGB image data of a document to luminance component and chromaticity component, an optimization process unit which converts the distribution state of the luminance component data and chromaticity component data so as to achieve a distribution from a minimum value to a maximum value of the data within a color space, an encoding process unit which encodes data of each pixel as code data obtained by quantization at a gradient level less than the data within a range of gradient distribution based on mean value information, a memory which stores mean value information, gradient range exponent, and code data of each block obtained by the encoding process in the encoding unit, a decoding process unit which decodes code data in block units based on the mean value information and gradient range exponent stored in the memory, and reverse optimization process unit which returns the distribution state of data of the luminance component and chromatict

Abstract: An image forming apparatus with a plurality of image forming units for forming an input image on a recording medium, a fixing unit for fusing the image formed on the recording medium to the recording medium, a fixing temperature detecting unit for detecting the temperature of the fixing unit, a registration pattern detecting unit for detecting a registration pattern formed by a plurality of image forming units, a calculator for determining a registration correction value for correcting the input image based on output from the registration pattern detecting unit, and an update requesting unit for requesting an update of the registration correction value. The update requesting unit requests an update of the registration correction value based on the temperature detected temperature of the fixing unit.

Abstract: In an image coding apparatus for encoding and decoding multi-level image data with block truncation coding, multi-level image data is divided into second blocks (e.g., 6*6 pixels) which is larger in size than a first block (e.g., 4*4 pixels) to be coded. Average value and gradation level amplitude are calculated on a second block, and encoding and decoding are performed on a first block by using the average value and gradation level amplitude. When a pixel not adjacent to the first block is included in an end of the image or the like in a second block, data of the actual pixels are used for the pixels having no data. Thus, deterioration of the image quality can be reduced.

Abstract: An image forming apparatus automatically identifying top and bottom of document image based on characteristics with regard to shapes or positions of data, etc. recorded on document. Distribution states of pixel cumulative values in main scanning direction and sub scanning direction of image signals provided by scanning the document, are analyzed and top and bottom of the document image is identified from the result of analysis. Further, it is possible to identify the top and bottom of the document image by analyzing the distribution states the pixel cumulative values in the main scanning direction and the sub scanning direction of the image signals and identifying letter series regions and line segment regions displaced therefrom.

Abstract: An image editing apparatus includes an image display apparatus for displaying a read image. An area of an image region displayed in the image display apparatus is determined by the size of the read image. For an image editing process, a frame which indicates an image editing region is displayed within the image region. A cursor is used to move the frame, where the cursor has a display shape which changes in accordance with a position of the frame.

Abstract: Image distortion is corrected in a color printer wherein print units for a plurality of colors are aligned to form a color image by superposing images formed by the print units. Images of the colors of a predetermined pattern formed by the print units are detected by a sensor. Based on the detection result, image distortion quantities and a setting error of the position of the sensor are detected. Then, the detected color shift on image forming is corrected according to the image distortion quantities and the setting error.